Back-pedaling brake.



No. 1537,:73.v

Patented Nov. I4, |899. E. s. STEM e. A. u. uuNLAP.

BAcK PEnALms BRAKE.

(Application led June 21, 1899.)

(No Model.)

W/ TNE SSE S ATTORNEY TH: nofws Bucks ca., Momma.. wAsNluufou. mA c.

UNITED STATES PATENT OEEICE.

EDGAR SAMUEL STEM AND ARTHUR ovEREIELD DUNLAP, E ALDERSON, PENNSYLVANIA.

BAoK-PEDALING BRAKE.

SPECIFICATION forming part of Letters Patent No. 637,178, dated November 14, 1899.

Application filed J une 2] 1899. Serial No. 721,292. (No model.)

To all whom t may concern:

Be it known that we, EDGAR SAMUEL STEM and ARTHUR OvERETELD DUNLAP, of Alderson, in the county of Luzerne and State of Pennsylvania, have invented a new and Improved Back-PedalingBrake,of which the following is a full, clear, and exact description.

This invention relates to a bicycle-gear for both chain and chainless wheels, and it re- Io lates to certain means for driving the wheel and for eectively braking the same.

This specification is the disclosure of one form of our invention, while the claims define the actual scope thereof.

Reference is to be had to the accompanying drawings, forming a part of this specication, in which similar characters of reference indicate corresponding parts in all the views.

Figure 1 is a longitudinal section of the zo gear. Fig. 2 is an end elevation with part of thev crank-hanger in section on the line-2 2 of Fig. 1. Fig. 3 is a sectional view ou the line 3 3 of Fig. 1, looking in the direction of the arrow a in said figure. Fig. 4 is a sec- 2 5 tional view on the line 4 4 of said figure, looking in the direction of the arrow a. in said gure; and Fig. 5 is a sectional view on the line 4 4 of Fig. 1, looking in the direction of the arrows 5 in said Fig. l.

The crank-hanger 6 carries with it,by means of suitable bearings 7, a sleeve 8, forming the trunnion for the gear of the gear 9, which gear transmits the motive force to the traction-wheel of the bicycle. The shaft 10, car- 3 5 rying the pedals 11, is mounted to turn in the sleeve 8 and is carried on suitable bearings 12. The crank-hanger has at one end a case 6a for the gear 9 and at the other enda cap 6b, which latter serves to hold in place 4o certainpartstobe hereinafterdescribed. The case 6 may be made in sections to facilitate its application to the gear.

Fast to the shaft 10 is a cross-arm 14, forming a clutch member. The ends of this arm 45 are cut eccentrically to the shaft 10 and carry antifriction-rollers in recesses formed in the arm. The arm 14 turns with the shaft, and the arm is located in a recess 16, formed in t-he face of the gear 9. This recess 16 also carries two shoes 17, forming coacting clutch members working with the arm 14. The shoes 17 have concentric outer edges bearing against the annular wall of the recess 16, and the inner edges of the shoes 17 have eccentric portions 18 formed thereon, such eccentric edges terminating in shoulders 19. The ends of the arm 14 respectively oppose the eccentric portions 18 of the shoes 17, and when the arm 14' turns with the shaft 10, so that the arm engages the shoulders 19, as shown in Fig. 2, the shoes 17 are caused to move with the shaft 10; but the shoes when the parts are so disposed are not forced outward. When the shaft turns the arm 14 in the opposite direction, the rollers 15, acting against the eccentric edges 18, force the shoes outward and bind them against the said annular Walls of the recess 16 in the gear 9, thus rendering the gear fast with the shoe. The shoes 17 have recesses 2O formed in their outer edges, and these recesses each contain antifriction-balls 2l, held in place by expansive springs 22. The inner walls of the recesses 2O are formed eccentrically, so that when the shoes turn freely around the shaft 10 by the engagement of the arm 14 with the shoulders 19 of the shoes the balls 2l bear against the gear 9, and thus reduce the friction existing between the two parts; but when the shoes bear in the opposite direction and are forced outward against the gear the balls 21 roll back within the deep portions of the recesses 20 and do not therefore exert this antifriction influence. The shoes 17 are connected to move toward and from each other by pins 32, which are fast to one shoe and slide loosely in sockets in the other shoe. The shoes are normally spread apart by springs 33, as shown in Fig. 2.

The shaft 10, at the end opposite the arm 14, carries a clutch member 23, which comprises eccentric edges 24 and recesses carrying antifriction balls or rollers 25. The eccentric edges 24 terminate in shoulders 26. An annulus 27 iits loosely within the crankhanger 6. A cam encircles the clutch member 23 and is held properly in place by the beforesaid cap 6*. Fitted between the annulus 27 Vnulns.

and the clutch member 23 are two shoes 28, similar to the shoes 17 and having therefore eccentric edges 29, shoulders 30, and antifriction-balls 31, all of a construction and arrangement described before. Vhen the shaft 10 engages the shoulders 2G with the shoulders 30, the shoes 28 are turned loosely within the annulus 27 and around with the shaft 10 and clutch member 23. Vhen the shaft 10 turns in the opposite direction, the rollers or balls 25, carried in the eccentric portions of the clutch member 23, are caused to impinge against the eccentric inner edges 29 of the shoes 28, thus forcing the shoes outward and causing them to bind with the annulus 27 to turn the annulus. The shoes 28 are connected by pins Si and springs 35, as previously described. The shoes 17 and 28 at the respective ends of the shaft 10 are disposed oppositely-that is to say, when the shaft 10 turns to fasten the shoes 17 with the clutch member 14, and thus drive the gear 9,the shoes 28 are turning idly with the clutch member 23, and when the shaft 10 is turned revolubly the shoes 17 are idle and the shoes 28 are engaged with the annulus 27 to turn said an- The parts should be so adjusted that when the shaft 10 turns to bind the shoes 17 with the gear 9 the gear will be turned to drive the bicycle forwardly, and when the shaft is turned in the opposite direction, so that the shoes 17 are rendered idle, the gear 9 will not be turned. Fastened rigidly on the left-hand end of the sleeve 8 of the gear 9 is a collar 37, against which act two brakestraps 3G. Each brake-strap is fastened at one end to the crank-hanger 6 by means of blocks 38, and the other end of each brakestrap is free, except that it is fastened to the annulus 27 through the medium of pins 39, fast te said annulus. Now when the annulus is idle the brake-straps 36 are lax; but when the annulus is engaged with the shoes 28, and therefore turned with the shaft 10, it is clear that the shoes 28 will be drawn tightly against the collar 37, and therefore that the sleeve 8 of the gear 0 will be braked. This tends to stop the movement of the gear 9, and consequently to brake the machine.

In using the apparatus the shaft 10 is driven by means of the pedals, and when the shaft is driven forwardly the clutch member 11 will throw the shoes 17 firmly against the gear 9, and thus drive the gear. Should it be desired to coast the machine, the driving of the pedals should be ceased, the rider simply retaining the pedals, but not moving them either forward or backward. The parts will now be free to run. Should it be desired to apply the brake, the pedals should be driven backward, which will cause the clutch member 23 to throw the shoes or coacting clutch members 28 outward against the annulus 27. This causes the annulus to turn and contracts the brake-straps 36 against the collar 37, and

thus stops the movement of the sleeve 8 of the gear S).

It will be observed that the shoulders 26 are calculated to move the shoes 28 around the inside of the annulus independently thereof rather than to force them out radially and that even should the shoes be forced out radially against the annulus this tendency will not be so great as to prevent the balls 31 from relieving the friction to an extent sufcient to permit theshoe circulating inside of the annulus and independently of the same. Should the annulus have a tendency to move from right to left, (in Fig. 3,) the brake-straps 36 would buckle outward away from the co1- lar and against the crank-hanger 6, thus not only relieving the sleeve 8 of all strain of the brake, but resisting further movement of the annulus.

Having thus described our invention, we claim as new, and desire to secure by Letters Patent- 1. In a bicycle-gear, the combination of a' crank-hanger, a gear proper havingasleeve, forming a trunnion for the gear, the sleeve being mounted to turn in the crank-hanger, a shaft mounted to turn in the sleeve, aclutch member fast to the shaft adjacent to the gear, an additional clutch member acting with the iirst-named clutch member and adapted to be engaged with the gear to turn the gear, a brake-strap having one end fast to the crankhanger, an annulus mounted to turn and having the other end of the brake-strap attached thereto, the brake-strap being adapted to contact with the sleeve, and additional coacting clutch members disposed oppositely to the first-named members and serving to connect the shaft with the annulus.

2. The combination with a support, of a sleeve mounted therein, a gear carried fast on the sleeve, a shaft mounted loosely in the sleeve, clutch devices driving the gear from the shaft, a brake-strap attached to the snpport, an annulus movable relatively to the support and carrying thefree end of the brakestrap, the brake-strap being adapted to contact with the sleeve, and a clutch workin g between the shaft and the annulus to turn the annulus, the two clutches being respectively operative by opposite movements of the shaft.

3. The combination with a support, of a gear mounted to turn thereon, a shaft juxtaposed to the gear, a clutch working between the gear and the shaft to drive the gear from the shaft, a brake-strap serving to restrain the movement of the gear, one end of the brakestrap having connection with the support, and a second clutch having connection with the other end of the brake-strap and with the drive-shaft to operate the brake-strap from the drive-Shaft, the two clutches being respectively operative by opposite movements of the shaft.

4. In brake mechanism, the combination IOO IIO

IIS

With a support, of a shaft revoiubiy mounted abrake-strap adapted to contact With the supadjacent thereto, a member mounted to turn port and actuated by the annulus. therewith and having an -eccentric edge terminating in a Shoulder, a shoe Working With ggmshgUNLAP 5 said member and having an eccentric edge and a shoulder opposing the edge and shoul- Witnesses:

der of said member, an annulus encircling GEO. T. KIRKENDALL,

the shoe and said member of the shaft, and GHAS. H. COOKE. 

